As a printing apparatus that forms an image such as a photograph of face and character information on a recording medium such as thick paper and plastic card, an apparatus has been known in which an image is formed once on a film-shaped transfer medium and the image formed on the transfer medium is printed and transferred onto a recording medium.
In this type of printing apparatus, an image is first thermally transferred (first transfer) onto a roll-shaped transfer film using a roll-shaped ink ribbon in which ink of a single or a plurality of colors is applied at certain intervals each of which corresponds to a card width of the recording medium, and next, the image of the transfer film is thermally transferred (second transfer) to the recording medium.
The ink ribbon and transfer film (hereinafter, these are collectively referred to as “film-shaped medium”) formed in the shape of a roll are stored in cassette cases in a state in which the medium is wound around a supply spool and a wind-up spool while being laid between both spools. Accordingly, unless the film-shaped medium shifts in the same direction without causing an error (deviation) from the direction in which the medium is fed out of the supply spool, it is not possible to form an image facing a printing surface of the recording medium to degrade printing quality.
When the film-shaped medium is the ink ribbon, a surface of the film that is a substrate of the ink ribbon is coated with sublimation ink, and the printing apparatus pulls an unused portion of the ink on the film out of the supply spool to nip with a thermal head and a platen roller in a state of overlapping the transfer film, and thereby sublimates the ink to the surface of the transfer film to print the image. However, the ink ribbon is not always transported in the pull-out direction, and is sometimes rewound in the direction of winding around the supply spool. For example, in a printing apparatus that prints selectively on two types of recording media of normal size and half size, an apparatus is known where in printing on the recording medium of the half size, since a half of an ink coat region of the ink ribbon used in one printing is wound with the ink unused, in next printing operation of the half size, the region with the ink unused portion is rewound to a transfer position to the transfer film and is used (see Patent Document 1).
However, when a rewound amount is large in rewinding the ink ribbon to use, a printing wrinkle tends to occur in printing due to winding fluctuations and the like. Therefore, in Patent Document 1, in the case of requiring rewinding with a certain amount or more, rewinding is not performed even in printing operation of the half size, and printing is performed with a portion of the ink ribbon located in a transfer position at this time to the transfer film.